Hopper-loading method and installation

ABSTRACT

A device for distributing loose materials, arranged in a curtain of loose material tipped out from a means of conveying loose material includes a box with a top opening, at least one wall which extends transverse to the curtain of material inside the box to subdivide the box into at least two compartments, and at least two tipping-out means, one of the tipping-out means being associated with each of the compartments of the box, the tipping-out means being directed in such a way as to deflect the material received in the respective compartments into a distinct region of the hopper. The method for loading a hopper includes tipping loose material out in the form of a curtain of material over the hopper and splitting the curtain into at least two partial streams so as to deflect each of the partial streams towards a distinct region of the hopper.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is entitled to the benefit of International ApplicationNo. PCT/EP04/00421 filed on Jan. 20, 2004, and Luxembourg PatentApplication No. 91 000 filed on Jan. 21, 2003.

FIELD OF THE INVENTION

The present invention relates to a hopper loading installation,particularly in a shaft furnace loading installation.

BACKGROUND OF THE INVENTION

To guarantee optimum charging of a shaft furnace, it is desirable forthe materials stored in the storage hopper to be distributed fairlyuniformly. However, it is difficult to distribute the charge materialsuniformly in the hopper because of the particle size of the chargematerial. The problem is that the charge material, whether it be ironore particles or coke particles, has a varying and non-uniform particlesize. As the material is conveyed towards the hopper, for example via aconveyor belt, the fine particles have a tendency to build up in largerproportions at the bottom of the layer of conveyed material, while thelarge particles remain in the upper part of the layer.

It then follows that when the material is tipped out of the conveyorbelt, the material drops in the form of a curtain of a certain width, ofwhich the rear layer, viewed in the direction of conveying, contains apredominance of large particles while the front layer contains more fineparticles. This distribution of the particles in the curtain of materialhas the effect that, after loading, the rear part of the hopper, viewedin the direction in which the material is conveyed, contains more largeparticles than the front part and that the distribution of material istherefore distinctly non-uniform.

In addition, when the charge material impacts the hopper, a naturalpouring cone is formed around the fall line. The largest and heaviestparticles therefore have a tendency to tumble along the slopes of thiscone, under the influence of their weight, toward the peripheral regionsof the chamber. By contrast, the smallest particles, known as “fines”have a tendency to remain in the central region of the pouring cone.This phenomenon further accentuates the segregation of the materialwithin the hopper.

To solve this problem, it has been proposed that the hopper be made torevolve about a vertical axis during loading. By virtue of the rotationof the hopper, the effects of the segregation in the curtain of materialon the distribution of the material in the hopper can be reduced.Unfortunately, the segregation of the material due to the pouring conewithin the hopper cannot be reduced. Such a rotary hopper cannottherefore meet the requirements of uniform charging of a shaft furnace.In addition, such a rotary hopper needs to be housed in the framework ofthe shaft furnace on rolling bearings. Given the size and weight of sucha hopper, this step entails a considerable investment and poses problemsin terms of installation maintenance.

OBJECTS AND SUMMARY OF THE INVENTION

The purpose of the present invention is to propose a method for loadinga hopper, which leads to a better distribution of the material in thehopper. Another object of the invention is to propose a device fordistributing loose material and a loading installation which allow thismethod to be performed.

According to the invention, this objective is achieved using a methodfor loading a hopper comprising the steps of

-   -   tipping loose material out in the form of a curtain of material        over said hopper, said curtain of material having a lateral        extent,    -   splitting said curtain into at least two partial streams, said        split being done transversely to said lateral extent, by means        of a laterally moveable deflector    -   deflecting each of said partial streams toward a distinct region        of the hopper.

By subdividing the curtain of material transversely to its lateralextent into several partial streams, it is possible to make sure thatthe large and fine particle composition of the partial streams isessentially the same. Indeed, if the distribution of material variesgreatly from the front of the curtain of material to the rear, viewed inthe direction in which the loose material is conveyed, it is, on theother hand, essentially constant in the direction of the lateral extentof the curtain, that is to say, from left to right. It then follows thatdividing the curtain and deflecting the partial streams toward distinctregions of the hopper makes sure that these different regions are loadedwith material of comparable composition. This on the whole guarantees abetter distribution of material, even though within the partial streams,the segregation phenomenon remains. By varying the position of thelaterally moveable deflector, it becomes possible to vary the partialflow width and therefore the amount of material contained in thesepartial streams.

In a preferred embodiment, the method further comprises the step ofregulating the flow rates of material in the partial streams byadjusting the points at which said curtain of material is split. Due tothe mechanisms associated with conveying material in loose form, eitheron a conveyor belt or using skip elevators, the curtain of material isgenerally thicker in the middle of the curtain than at the outerregions. As a result, the material content of the curtain is higher atthe middle of the curtain than on its outside. By choosing the points atwhich the curtain is split with care, this difference in materialcontent can easily be compensated for. If, for example, the curtain issplit into four adjacent partial streams, then the curtain will besubdivided in such a way that the central partial streams are narrowerthan the outer streams.

In order to ensure good distribution of the material in the hopper, thepoints at which said curtain of material is split are chosen to make theflow rates of material in said partial stream equal.

According to the invention, a device for distributing loose material,which is intended to be arranged in a curtain of loose material tippedout from a means of conveying loose material, comprises a box with a topopening, at least one wall which extends transversely with respect tosaid curtain of material inside said box in such a way as to subdividesaid box into at least two compartments, and at least two tipping-outmeans, one of said tipping-out means being associated with each of thecompartments of said box, said tipping-out means being directed in sucha way as to deflect the material received in the respective compartmentsinto a distinct region of the hopper, and a deflector arranged above thesaid wall, said deflector being laterally moveable with respect to saidwall.

Placed in the curtain of loose material, the dividing wall or wallsseparating the compartments of the box split the curtain of materialinto several partial streams of comparable composition. The partialstreams are received in the respective compartments of the box anddeflected by the tipping-out means into distinct regions of the hopper.

It should be noted that the fact of splitting the curtain of materialtransversely to its lateral extent ensures essentially equal compositionin the partial streams even if the tipping-out point is offset from thecentral axis of the hopper.

In order to regulate the flow rate of different partial streams, thedevice comprises at least one deflector arranged above one of the walls,said deflector being laterally moveable with respect to said wall. Thedeflector comprises, for example, a moving crossmember of a certainwidth, which extends over the wall. By varying the position of thedeflector with respect to the wall, it is possible to modify the widthof the top opening of the two compartments adjacent to this wall. Itthen becomes possible to vary the partial flow width and therefore theamount of material received in each of these compartments. It should benoted that not all of the walls have to be fitted with a deflector.Indeed, in order to be able to regulate the flow rates of the partialstreams effectively, it is sufficient for at least one of the walls ofeach compartment to be equipped with such a deflector.

Said wall or walls preferably extend up to the height of the top openingof the said box. Thus, the curtain is effectively split as soon as itenters the box. This ensures a constant ratio between the amounts ofmaterial tipped out into the different regions of the hopper, even ifthe rate of tipping out differs from one tipping-out means to another.

In an alternative form of the invention, said tipping-out means comprisechutes extending laterally from said box and a bottom of eachcompartment is inclined toward the respective chute. The chutes may bemounted on the box via a suitable fixing means. In a preferred version,however, each chute is integral with the compartment with which it isassociated.

In another alternative form, the box is formed by the feed ends ofindividual chutes. In this alternative form, said tipping-out meanscomprise chutes oriented in distinct directions, said chutes beingarranged one beside the other so as to form said box having a topopening. The walls of said chutes which extend transversely with respectto said curtain of material then delimit the compartments in said box.

As loose materials often have abrasion properties, it is preferable forthe surfaces exposed to the curtain of material or to the partialstreams to be coated with an abrasion-resistant material.

The present invention finally relates to a hopper loading installationcomprising a means of conveying loose material, said means for conveyingloose material tipping the loose material out into a region situatedabove said hopper in the form of a curtain of material, and a device fordistributing loose material as described hereinabove.

Such an installation finds an application in all fields in which auniform distribution of loose material is desired. It must be noted thatthe application to loading a chute furnace is merely one example. Inaddition, it will be obvious that the advantages of the presentinvention are achieved independently of the conveying means. Hence, thelatter may, for example, comprise a conveyor belt or a skip elevatordevice.

BRIEF DESCRIPTION OF THE DRAWINGS

Other particulars and features of the invention will become apparentfrom the detailed description of several advantageous embodiments setout hereinbelow by way of illustration with reference to the appendeddrawings. They show:

FIG. 1: a front view of a hopper loading installation;

FIG. 2: a side view of the installation of FIG. 1;

FIG. 3: a plan view of a device for distributing loose material;

FIG. 4: a section on A-A through the device of FIG. 3;

FIG. 5: a section on B-B through the device of FIG. 3;

FIG. 6: a section on C-C through the device of FIG. 3;

FIG. 7: a detail of the fixing of the deflector crossmembers.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 and 2 respectively show a front view and a side view of aninstallation 10 for loading a hopper 12. The installation 10 comprises aconveyor belt 14 which conveys the loose material 16 over the hopper 12.The loose material is tipped out more or less over the central axis ofthe hopper 12 and therefore falls in the form of a curtain of material18 into the top opening of the hopper 12.

To ensure good distribution of the loose material within the hopper, adevice 20 for distributing loose material is arranged in the top openingof the hopper 12.

The device 20 comprises several chutes 22, 24, 26, 28, which areoriented in distinct directions so as to tip the loose material out intodifferent regions of the hopper. The different chutes are mounted sideby side in a top frame 30, so as to form a box 32 which is open at thetop and divided into several adjacent compartments by walls 34 of thechutes. The chutes are produced in such a way that the walls delimitingthe compartments extend at right angles to the curtain of material, thatis to say at right angles to the lateral extent of the curtain 18.

It should be noted that the chutes 24 and 28 extend at right angles tothe associated compartments. In order to guarantee a good flow of loosematerial along these chutes, the bottoms of these associatedcompartments comprise plates that are inclined toward the respectivechutes.

It should be noted that because of the lateral distribution of thecurtain of material, the outer compartments are preferably wider thanthe inner compartments. This is because, due to the mechanismsassociated with the conveying of loose material either by a conveyorbelt or using a skip elevator, the curtain of material is generallythicker in the middle of the curtain than in the outer regions. Theresult of this is that the material content of the curtain is higher atthe middle of the curtain than on its outside. This lateral distributionof the stream of material is clearly visible in FIG. 1.

In order to be able to vary the opening of the different compartments,and therefore vary the amount of material received in the differentcompartments, some walls are equipped, at their other ends, withmoveable crossmembers 38. These moveable crossmembers 38 are laterallymoveable with respect to the associated wall and thus allow the openingof the adjacent compartment to be enlarged or reduced.

It should be noted that all the surfaces exposed either to the curtainof material or to the partial streams inside the chutes are preferablycoated with a layer of abrasion-resistant material 40 and/or fitted withwearing plates 42.

1. A method for loading a hopper in a shaft furnace installationcomprising the steps of: a) tipping out loose material over said hopperin such a way as to cause said loose material to fall in the form of acurtain of material, said curtain of material having a lateral extent,b) splitting said curtain into at least two partial streams by means ofa laterally moveable deflector arranged in said curtain of material saidsplitting being done transversely to said lateral extent, c) deflectingeach of said partial streams towards a different region of the hopper.2. The method according to claim 1, comprising the step of regulatingthe flow rates of material in the partial streams by adjusting thelocations at which said curtain of material is split.
 3. The methodaccording to claim 1, wherein the locations at which said curtain ofmaterial is split are chosen so that the flow rates of material in saidpartial streams are equal.
 4. A device for distributing loose materialin a hopper, said device for being arranged in a curtain of loosematerial tipped out from a means of conveying loose material, saiddevice comprising: a) a box with a top opening, b) at least one wallwhich extends transversely with respect to said curtain of loosematerial inside said box in such a way as to subdivide said box into atleast two compartments, c) at least two tipping-out means, one of saidtipping-out means being associated with each of the compartments of saidbox, said tipping-out means being directed so as to deflect the materialreceived in the respective compartments into a distinct region of thehopper, and d) at least one deflector arranged above the said wall forsplitting said curtain of loose material into at least two partialstreams, said deflector being laterally moveable with respect to saidwall.
 5. The device according to claim 4, wherein said wall extends upto the height of the top opening of said box.
 6. The device according toclaim 4, wherein said tipping-out means comprise chutes extendinglaterally from said box and wherein a bottom of each compartment isinclined towards the respective chute.
 7. The device according to claim6, wherein each chute is integral with the compartment with which it isassociated.
 8. The device according to claim 4, wherein said tipping-outmeans comprise chutes oriented in distinct directions, said chutes beingarranged one beside the other so as to form said box having a topopening, the walls of said chutes which extend transversely with respectto said curtain of loose material delimiting the compartments in saidbox.
 9. The device according to claim 4, wherein the surfaces exposed tothe curtain of loose material or to the partial streams are coated withan abrasion-resistant material.
 10. The device according to claim 4comprising several walls which extend transversely with respect to saidcurtain of loose material inside said box so as to subdivide said boxinto several adjacent compartments, and wherein said at least onedeflector arranged above one of said walls.
 11. A hopper loadinginstallation for loading a hopper comprising a means of conveying loosematerial, said means for conveying loose material tipping the loosematerial out into a region situated above said hopper in the form of acurtain of material, and a device for distributing loose material, saiddevice being arranged in said region above said hopper with respect tosaid means of conveying loose material in such a way as to be situatedin said curtain of loose material when said means of conveying loosematerial tips out the loose material into said region, said device fordistributing loose material comprising: a) a box with a top opening, b)at least one wall which extends transversely with respect to saidcurtain of material inside said box in such a way as to subdivide saidbox into at least two compartments, c) at least two tipping-out means,one of said tipping-out means being associated with each of thecompartments of said box, said tipping-out means being directed so as todeflect the material received in the respective compartments into adistinct region of the hopper, and d) at least one deflector arrangedabove the said wall for splitting said curtain of loose material into atleast two partial streams, said deflector being laterally moveable withrespect to said wall.
 12. The hopper loading installation according toclaim 11, wherein the conveying means comprises a conveyor belt or askip elevator device.
 13. The hopper loading installation according toclaim 11, wherein said wall extends up to the height of the top openingof said box.
 14. The hopper loading installation according to claim 11,wherein said tipping-out means comprise chutes extending laterally fromsaid box and wherein a bottom of each compartment is inclined towardsthe respective chute.
 15. The hopper loading installation according toclaim 11, wherein each chute is integral with the compartment with whichit is associated.
 16. The hopper loading installation according to claim11, wherein said tipping-out means comprise chutes oriented in distinctdirections, said chutes being arranged one beside the other so as toform said box having a top opening, the walls of said chutes whichextend transversely with respect to said curtain of material delimitingthe compartments in said box.
 17. The hopper loading installationaccording to claim 11, wherein the surfaces exposed to the curtain ofmaterial or to the partial streams are coated with an abrasion-resistantmaterial.
 18. The hopper loading installation according to claim 11comprising several walls which extend transversely with respect to saidcurtain of material inside said box so as to subdivide said box intoseveral adjacent compartments, and wherein said at least one deflectoris arranged above one of said walls.
 19. The method according to claim2, wherein the locations at which said curtain of material is split arechosen so that the flow rates of material in said partial streams areequal.